#include <stdio.h>

int main()
{
	char str[]="aaaabcedfdsbasdbeascbacbacbcacbeaccebecacsaceba";
	int i, j ,tail = 1, len;

	for (i=0; str[i]; i++);
	len = i;

	for (i=0; i < len; ++i) {
		for (j=0; j < tail; j++)
			if (str[i] == str[j])
				break;

		if (j == tail) {
			str[tail] = str [i];
			tail ++;
		}
	}
	str[tail] = 0;

	printf("%s", str);
	return 0;
}
